Apparatus and method for generating three-dimensional layered objects

Abstract

A method for generating a three-dimensional layered object (T). The method comprises the steps of depositing a first liquid (9) on a flat support surface (3) of a cooled platform, where the first liquid (9) solidifies to form a first restraining layer H1; depositing a second liquid (11) on the first restraining layer H1, where the second liquid (11) solidifies to form a first structural layer G2 of the three-dimensional object, where the structural layer G2 is deposited in an area having a contour corresponding to a contour of a first cross-section of a digital model of the three-dimensional object; forming a second restraining layer H2 that completely surrounds the structural layer G2 in the directions X and Y; repeating the preceding steps for all cross-sections n of the three-dimensional model, thus producing an object formed by n superimposed structural layers G2, G3, ... Gi, ... Gn and enclosed at the bottom and at the sides along the directions X and Y by n+1 restraining layers H1, H2, ... Hi, ... Hn+1; and melting the restraining layers to release the three-dimensional layered object thus formed.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This patent application claims priority to Italian Patent Application No. 102022000018051, filed September 2, 2022, the entire disclosure of which is incorporated herein by reference.

[0002] The present invention relates to an apparatus for generating a three-dimensional layered object and a method for generating a three-dimensional layered object. [Background technology]

[0003] European Patent No. EP 2285552, by the same inventor, describes a method for producing a three-dimensional object formed by multiple superimposed layers of a liquid-based photosensitive material at room temperature and capable of permanently solidifying upon the action of electromagnetic radiation. The method described in this patent includes the steps of depositing a substrate on a modeling platform arranged in a cooling chamber so that the substrate reversibly solidifies to form a layer of solid material, selectively exposing the solid layer to electromagnetic radiation in one or more predetermined areas defined based on a cross-section of a three-dimensional model of the object to be produced so that the substrate irreversibly solidifies, and repeating the deposition and selective exposure operations for all cross-sections of the model of the three-dimensional object.

[0004] At the end of these operations, an object is formed comprising multiple irreversibly solidified superimposed layers surrounded by reversibly solidified layers. With increasing temperature, the reversibly solidified layers return to a liquid state, thus releasing the three-dimensional object. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] European Patent No. EP2285552 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides A. Limiting the consumption of materials for the creation of three-dimensional objects; B. Expanding the range of applications to include non-photosensitive materials; C. For lost-wax microcasting applications, using molten wax as the material for three-dimensional objects; D. Using readily available, low-cost support materials to generate three-dimensional objects and ensuring full consideration of the environment; E. Ensuring maximum accuracy and print quality; F. Ensuring maximum print uniformity; G. Ensuring the detachment of three-dimensional objects without manual intervention of the operator; Ensuring the release of three-dimensional objects without the use of solvents, and H. Lowering operating costs We aim to achieve this. [Means for solving the problem]

[0007] These objects are achieved by the present invention in that it relates to an apparatus of the kind specified in claim 1 and to a method specified in claim 7.

[0008] The present invention will be illustrated with reference to the accompanying drawings which represent preferred, non-limiting embodiments. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of an apparatus implemented in accordance with the teachings of the present invention; [Figure 2] FIG. 1 shows a first step of the method according to the invention. [Figure 3] FIG. 2 shows a second step of the method according to the invention. [Figure 4] FIG. 3 shows a third step of the method according to the invention. [Figure 5] FIG. 4 shows a fourth step of the method according to the invention. [Figure 6] FIG. 5 shows a fifth step of the method according to the invention. [Figure 7] FIG. 6 illustrates a sixth step of the method according to the invention. [Figure 8] FIG. 7 shows the seventh step of the method according to the invention. [Figure 9] FIG. 8 illustrates the eighth step of the method according to the invention. [Figure 10] FIG. 10 is a diagram showing steps for repeating the steps of FIGS. 2 to 9. [Figure 11] FIG. 10 is a diagram showing steps for repeating the steps of FIGS. 2 to 9. [Figure 12] FIG. 2 illustrates the terminal step of the method according to the invention. [Figure 13] FIG. 2 illustrates the terminal step of the method according to the invention. [Figure 14] FIG. 2 illustrates the terminal step of the method according to the invention. [Figure 15] FIG. 15 shows a first modification of the method described in the preceding FIGS. 2 to 14. [Figure 16] FIG. 15 shows a second modification of the method described in the preceding FIGS. 2 to 14. DETAILED DESCRIPTION OF THE INVENTION

[0010] FIG. 1 shows a schematic diagram of an apparatus 1 for producing a three-dimensional layered object T.

[0011] The apparatus 1 comprises a modelling platform 2 (represented diagrammatically in the figure) on which a three-dimensional object T is formed, the modelling platform 2 comprising a support surface 3 made by known techniques and movable along a direction Z in a reversible linear motion by thrust of actuator means (not shown) which in turn are controlled by an electronic unit 4 (shown diagrammatically).

[0012] Preferably, the direction Z is transverse, in particular perpendicular, to the support plane 3 .

[0013] In other words, the support plane 3 is preferably horizontal and the direction Z is preferably vertical.

[0014] The modeling platform is housed within the print chamber 6 .

[0015] More particularly, the modeling platform 2 is preferably housed in a modeling chamber 5 which defines therein a print chamber 6 within which the support plane 3 moves. The modeling chamber 5 is open at the top.

[0016] The apparatus 1 further comprises at least one cooling device 7 (schematically represented) designed to cool the print chamber 6 to a predetermined temperature, preferably below 0°C.

[0017] Preferably, a cooling device 7 is associated with the modelling chamber 5 .

[0018] Preferably, the electronic unit 4 is operatively connected to the cooling device 7 so as to be able to control the operation thereof in use.

[0019] In particular, the electronic unit 4 is preferably configured to be able to activate the cooling device 7 on command so as to bring the temperature inside the print chamber 6 to the above-mentioned predetermined temperature, i.e., preferably below 0°C.

[0020] In addition, the electronic unit 4 is preferably configured to be able to stop the cooling device 7 on command so that the temperature inside the print chamber 6 can exceed the predetermined temperature, i.e. so that the temperature inside the print chamber 6 can rise to about room temperature (around about 20°C).

[0021] Various types of cooling devices can be used, for example using a coolant circulated through a cavity (not shown) of the modeling chamber 5 or using a Peltier cell (not shown).

[0022] The modeling platform 2 is also cooled as it is located inside the print chamber 6. Additional cooling of the support plane 3, such as a Peltier cell (not shown), can also be used.

[0023] Located above the print chamber 6 is a first selective deposition device 8 for a first liquid 9 designed to generate a support layer of a three-dimensional object; a second selective deposition device 10 for a second liquid 11 designed to generate a structural layer of the three-dimensional object; a selective irradiation device 12 designed to generate thermal radiation 13 (e.g., a laser beam), and A leveling device 14 for previously deposited layers, designed to process the deposited layer to produce a surface parallel to the horizontal plane XY.

[0024] Preferably, the plane X_Y is transverse to the direction Z. In particular, the plane X_Y is advantageously perpendicular to the direction Z.

[0025] The above-mentioned apparatus is shown diagrammatically, with a first selective deposition device 8 movable in the plane X_Y relative to the modelling platform 2 and comprising a first nozzle 15 designed to eject a first liquid 9, preferably in the form of droplets.

[0026] The second selective deposition device 10 is movable in the plane X_Y relative to the modelling platform 2 and comprises a second nozzle 16 designed to eject a second liquid 11, preferably in the form of droplets.

[0027] The selective irradiation device 12 comprises an end 17 from which the thermal radiation emerges, which can be provided in a concentrated point form or in a diffuse form. Preferably, the end 17 is also movable in the plane X_Y relative to the modeling platform 2.

[0028] Finally, the leveling device 14 comprises a mobile milling cutter 18 which is also movable in the plane X_Y relative to the modeling platform 2 .

[0029] The first liquid 9 has a melting temperature T1 such that when it is ejected by the nozzle 15 onto the modeling platform and the print chamber 6 cools, it changes state, going from a liquid state to a solid state. Conveniently, but not exclusively, the first liquid is formed by water, which solidifies at a melting temperature T1 below 0 degrees Celsius (°C) at a pressure of 1 atmosphere.

[0030] In other words, the melting temperature T1 is preferably higher than the above-mentioned predetermined temperature.

[0031] The second liquid 11 has a melting temperature T2 such that when it is dispensed onto the modelling platform by the nozzle 16, it changes state, passing from a liquid state to a solid state. Suitably, but not exclusively, the second liquid is a molten wax that solidifies for a melting temperature below 60°C-78°C. The melting temperature T2 is higher than the melting temperature T1, such that the second liquid remains solid at room temperature, i.e., preferably in the range of 5°C to 35°C, and more advantageously at a temperature around 20°C.

[0032] In other words, the melting temperature T2 is preferably higher than the above-mentioned predetermined temperature, preferably higher than room temperature. Advantageously, the melting temperature T2 is higher than 20°C, more particularly it is higher than 35°C.

[0033] In use, the cooling device 7 is powered by thermal conduction, bringing the temperature of the print chamber 6 and of the modelling platform 2 below the melting temperature T 1 of the first liquid 9 .

[0034] The steps of the method according to the invention will now be clarified, which are controlled by the electronic unit 4. The electronic unit 4 is provided with an internal memory in which a three-dimensional model of the three-dimensional layered object T to be generated is stored. Such a three-dimensional model comprises the contours of a plurality of successive cross sections of the three-dimensional object and the coordinates of points defining the inner extent of the contours.

[0035] The method preferably provides for bringing the temperature inside the print chamber 6 to said predetermined temperature, ie preferably below 0°C.

[0036] More particularly, the method provides for activating / operating the cooling device 7 in such a way as to bring the temperature inside the print chamber 6 to said predetermined temperature, ie preferably below 0°C.

[0037] First step - selective deposition of a first liquid and formation of a layer H1. FIG. 2 shows a first step of the method according to the invention implemented by the device 1 .

[0038] The support plane 3 is placed at the upper machining start position (home position).

[0039] A first selective deposition device 8, which moves in plane X_Y under the control of the electronic unit 4, deposits a liquid 9 onto the horizontal support surface 3, which solidifies immediately upon contact with the support surface 3 to form a first restraining layer H1. The first restraining layer H1 defines an area that is larger than the area of ​​the largest cross section of the three-dimensional model that defines the object to be generated.

[0040] Second step - planarization of the first layer H1. FIG. 3 shows the second step of the method according to the invention.

[0041] A second step of the method according to the invention preferably provides for planarizing, i.e. shaping / leveling / grinding, the face 20 of the first restraining layer H1 facing away from the support plane 3, advantageously by means of a material removal process, so that said face 20 is preferably flat and / or coplanar with the plane X_Y and / or parallel to the support plane 3.

[0042] More specifically, the leveling device 14 flattens / levels the surface 20 of the first restraining layer H1, preferably facing in the opposite direction to the support plane 3, by moving the milling cutter 18 on the plane X_Y, thus creating a first flat surface 20 and ensuring a constant thickness D1 of the first restraining layer H1.

[0043] Third step - Lower the support plane. FIG. 4 shows the third step of the method according to the invention.

[0044] An electronic unit 4 commands the modeling platform 2 to move the support plane 3 along Z, i.e. preferably transversely, in particular orthogonally, to the plane X_Y, and towards the bottom of the print chamber 6 by a predetermined amount, in particular an amount equal to the thickness of the successive layers to be produced. In order to optimize the printing time as a function of the surface quality of the final object, use is often made of a "variable layer thickness" technique, in which each layer can have a thickness different from the previous one.

[0045] Fourth step - selective deposition of a second liquid and formation of layer G2. FIG. 5 shows the fourth step of the method according to the invention.

[0046] A second selective deposition device 10, which moves in the plane X_Y under the control of the electronic unit 4, deposits, in particular selectively deposits, a second liquid 11 onto the previously formed first stop layer H1, which solidifies immediately upon contact with the first layer H1 to form a first structural layer G2 of the three-dimensional object having a substantially constant thickness. The structural layer G2 is deposited in an area having a contour and an area corresponding to the contour and an area of ​​a first cross section of the digital model of the three-dimensional object. As mentioned above, the three-dimensional model of the object to be generated is stored in the electronic unit 4.

[0047] The first structural layer G2 defines an area smaller than the area of ​​the first restraining layer H1 and is preferably disposed across a central portion of the first restraining layer H1.

[0048] Fifth step - melting of the edges of layer G2. FIG. 6 shows an optional fifth step of the method according to the invention.

[0049] The electronic unit 4 commands the movement of the selective irradiation device 12 so that the thermal radiation 13 causes the melting of the side edges of the structural layer G2, which are perpendicular to the plane X_Y. This operation is useful when the second liquid 11 is made of molten wax. The wax is actually released in small droplets that, upon cooling, give the side edges of the structural layer G2 an irregular wrinkle profile. The melting and subsequent solidification of the edges of the structural layer G2 contributes to reducing the graininess of the edges and "flattening" these edges. Preferably, the melting is performed within the area within the edges of the structural layer to ensure homogeneity and reduce the graininess. This non-compulsory option is used to ensure material homogeneity within the model to be generated.

[0050] Sixth step - selective deposition of the first liquid and formation of layer H2. FIG. 7 shows the sixth step of the method according to the invention implemented by the device 1.

[0051] A first selective deposition device 8, which moves in the plane X_Y under the control of the electronic unit 4, deposits a liquid 9 onto the stopping layer H1 only in areas not affected by the structural layer G2, which solidifies immediately on contact with the layer H1 to form a second stopping layer H2 which completely surrounds the structural layer G2 in the direction X and in the direction Y, i.e. advantageously parallel to the plane X_Y, and has a thickness which is substantially constant and / or substantially equal to the thickness of the structural layer G2.

[0052] In other words, the direction X and the direction Y are preferably transverse, in particular perpendicular to the direction Z.

[0053] Seventh step - planarization of layers G2 and H2. FIG. 8 shows the seventh step of the method according to the invention.

[0054] The seventh step of the method according to the invention preferably provides for planarizing, i.e. shaping / leveling / grinding, advantageously by means of a material removal process, the faces 19a of the second restraining layer H2 and the faces 19b of the structural layer G2 facing away from the support plane 3, so that said faces 19a and 19b are preferably flat and / or coplanar with respect to the plane X_Y and / or parallel to the support plane 3.

[0055] More specifically, the leveling device 14 preferably moves a milling cutter 18 in the plane X_Y to flatten / level the surface 19a of the second control layer H2 facing away from the support plane 3 and the surface 19b of the structural layer G2 facing away from the support plane 3. These surfaces 19a and 19b are made flush, ensuring a constant thickness of the first structural layer G2 and of the second control layer H2. The deposited second layer may have a thickness different from that of the first layer.

[0056] Eighth step - Lower the support plane. FIG. 9 shows the eighth step of the method according to the invention.

[0057] The electronic unit 4 commands the modeling platform 2 to move the support plane 3 again along Z, i.e. preferably transversely, in particular orthogonally, to the plane X_Y, and towards the bottom of the print chamber 6 by a predetermined amount, in particular an amount equal to the thickness of the successive layer to be produced.

[0058] Repeat the fourth, fifth, seventh and eighth steps. The fourth step is repeated to deposit a second liquid 11 on the structural layer G2 and form a structural layer G3 (FIG. 10). The structural layer G3 is deposited in an area having a contour corresponding to the contour and contour of the second cross section of the digital model of the three-dimensional object.

[0059] Then, possibly after melting the edges of the structural layer G3 or possibly after melting the entire structural layer G3, the sixth step is repeated, in which a liquid 9 (FIG. 11) is deposited on the control layer H2 and / or on the structural layer G2 in areas not affected by layer G3, and solidifies immediately on contact with the control layer H2 / the underlying structural layer G2. Thus, similar to what is shown for the sixth step, a third control layer H3 is created, completely surrounding the structural layer G3 in the direction X and the direction Y, i.e. advantageously parallel to the plane X_Y, and having a substantially constant thickness relative to the thickness of layer G3. The layers G3 and H3 are then machined and flattened with a milling cutter 18 to make them flush. Finally, the horizontal plane 3 is lowered.

[0060] Repetition of these steps for all cross sections n of the three-dimensional model makes it possible to generate an object formed by n superimposed structural layers G2, G3, ... Gi, ... Gn and surrounded at the bottom and at the sides (i.e. along X and Y) by n+1 restraining layers H1, H2, ... Hi, ... Hn+1.

[0061] At the end of the completed iterations, the cooling device 7 is turned off (FIG. 13), so that the temperature of the chamber 6 rises to room temperature (e.g., about 20°C) and exceeds the melting temperature Tl, so that the restraining layer spontaneously returns to a liquid state, thus releasing the three-dimensional layered object thus formed. At room temperature (e.g., about 20°C), the second liquid remains in a solid state because room temperature is lower than the melting temperature T2.

[0062] The three-dimensional object T thus formed can be removed from the modeling platform 2 (FIG. 14).

[0063] The following advantages are thus achieved: A. The deposition of material on the object occurs selectively, limiting its consumption and consequently reducing operating costs. B. The material of the object can be of a non-photosensitive type, which greatly expands the range of applications and reduces the operating costs. C. For lost-wax microcasting applications, the material forming the three-dimensional object can be molten wax, which features a lower melting temperature than photosensitive resins, ensuring full compatibility with the heat treatment process of these processes, resulting in improved melting quality and reduced operating costs. D. The support material can consist of water, which significantly reduces the operating cost and ensures full consideration for the environment. E. A planarization step at the end of the deposition of each layer ensures maximum precision and print quality in the direction of axis Z. F. An optional melting step of the edges of the layer Gn ensures maximum precision and print quality in the direction of the axes XY. G. An optional melting step of the entire cross section of layer Gn ensures maximum print homogeneity in the direction of the axes X and Y. H. The spontaneous melting of the support layer Hn upon returning to room temperature ensures the detachment of the 3D object without manual intervention by the operator, avoiding possible damage to the 3D object caused by the manipulation and by the separation of the support structure. I. The spontaneous melting of the support layer Hn upon returning to room temperature ensures the release of the 3D object without the use of solvents, avoiding possible damage to the model caused by chemical action, thus reducing its operating costs and ensuring overall environmental friendliness.

[0064] According to what is shown in the sixth step, the stop layer H2 is deposited only in the areas not affected by the structural layer G2.

[0065] Alternatively, a stop layer H2 may be deposited both on top of the structural layer and on areas not affected by the structural layer (see FIG. 15). A subsequent planarization operation (seventh step) serves to eliminate the first solidified liquid disposed on top of the structural layer.

[0066] According to an alternative variant of Figure 16, following the deposition operation of the fourth step, a uniform thermal irradiation of the previously deposited structural layer G2 is activated using an irradiation device - alternatively to what is shown in Figure 6 - in order to ensure the homogeneity of the layer itself. [Explanation of symbols]

[0067] 1. Device for generating three-dimensional objects 2. Modeling Platform 3 horizontal support plane 4 Electronic Unit 5. Modeling Chamber 6 print chamber 7 Cooling device 8. First selective deposition device 9. First Liquid 10 Second selective deposition device 11 Second Liquid 12 Selective irradiation device 13 Thermal radiation 14 Leveling device 15 First nozzle 16 Second Nozzle 17 End 18 Milling cutter 19a, 19b side 20 sides G2 First structural layer G3 Second structural layer H1 First stopping layer H2 Second stopping layer H3 Third layer of protection T 3D layered object

Claims

1. 1. An apparatus (1) for generating a three-dimensional layered object (T), wherein a modeling platform (2) defines a support plane (3) housed in a print chamber (6), The device (1) further comprises a cooling device (7) designed to cool the print chamber (6), The device (1) a first selective deposition device (8) for a first liquid (9); a second selective deposition device (10) for a second liquid (11); Equipped with the first liquid (9) has a melting temperature (T1) such that when the first liquid (9) is dispensed onto the modeling platform (2) and the print chamber (6) is cooled, the first liquid (9) changes state, transitioning from a liquid state to a solid state; the second liquid (11) has a melting temperature (T2) such that when the second liquid (11) is dispensed onto the modeling platform, the second liquid (11) changes state, transitioning from a liquid state to a solid state; the melting temperature (T2) is higher than the melting temperature (T1); The modeling platform (2), the first selective deposition device (8), the second selective deposition device (10), and the cooling device (7) a) depositing the first liquid (9) on the support surface (3), the first liquid (9) solidifying immediately upon contact with the support surface (3) to form a first containment layer (H1), the first containment layer (H1) defining an area greater than the area of ​​the largest cross section of a three-dimensional model defining the three-dimensional layered object (T) to be generated; b) planarizing the face (20) of the first restraining layer (H1) facing away from the support plane (3) to create a first flat face (20) that is coplanar with respect to the plane (X_Y) and ensures a constant thickness (D1) of the first restraining layer (H1); c) depositing the second liquid (11) on the previously formed first stop layer (H1), the second liquid (11) solidifying immediately upon contact with the first stop layer (H1) to form a first structural layer (G2) of the three-dimensional layered object (T), the first structural layer (G2) being deposited in an area having a contour corresponding to the contour of a first cross section of a digital model of the three-dimensional layered object (T); d) depositing the first liquid (9) on the first restraining layer (H1), at least in the area not affected by the first structural layer (G2), the first liquid (9) solidifying immediately upon contact with the first restraining layer (H1) to form a second restraining layer (H2) completely surrounding the first structural layer (G2) in the direction X and the direction Y; e) planarizing the face (19a) of the second control layer (H2) facing away from the support plane (3) and the face (19b) of the first structural layer (G2) facing away from the support plane (3), thus making these faces flush and ensuring a constant thickness of the first structural layer (G2) and of the second control layer (H2); f) repeating steps c), d) and e) for all cross sections n of the three-dimensional model, thus generating an object formed by n superimposed structural layers (G2, G3, ... Gi, ... Gn) and surrounded at the bottom and at the sides along the direction X and the direction Y by n+1 blocking layers (H1, H2, ... Hi, ... Hn+1); deactivating the cooling device (7) so that the temperature of the print chamber (6) exceeds the melting temperature T1 and the restraining layers (H1, H2, ... Hi, ... Hn+1) spontaneously return to a liquid state, releasing the three-dimensional layered object (T) thus formed; The device is movable / operable under the control of an electronic unit (4) to perform the above.

2. the support plane (3) is movable along a direction transverse to the plane (X_Y), in particular along a direction perpendicular to the plane (X_Y), the device (1) further comprises an electronic unit (4) configured to control the movement of the support surface (3); 2. The apparatus of claim 1, wherein the electronic unit (4) is configured to command a displacement of the support plane (3) relative to the print chamber (6) by a predetermined amount following steps b) and e).

3. 3. The apparatus according to claim 1, further comprising a selective irradiation device (12) designed to generate thermal radiation (13) used for selective irradiation of the second liquid (11), and wherein the electronic unit (4) is configured to command a movement of the selective irradiation device (12) following step c) such that the thermal radiation (13) causes melting of lateral edges of the corresponding structural layers (G2, G3, ... Gi, ... Gn), the lateral edges of the corresponding structural layers (G2, G3, ... Gi, ... Gn) being perpendicular to the plane (X_Y), this movement causing melting of the edges, which subsequently solidify and reduce the graininess of the edges themselves.

4. 3. The apparatus according to claim 1 or 2, wherein the apparatus (1) further comprises a selective irradiation device (12) designed to generate thermal radiation (13) and to activate a uniform thermal irradiation of the previously deposited structural layers (G2, G3, ... Gi, ... Gn).

5. 5. The device according to claim 1, wherein in step d) the second stopping layer (H2) is deposited only in areas not affected by the first structural layer (G2).

6. 5. The device according to claim 1, wherein the second blocking layer (H2) is deposited both on top of the first structural layer (G2) and on areas not affected by the first structural layer (G2), and the subsequent step e) contributes to eliminating the solidified first liquid located on top of the structural layer (G2).

7. 1. A method for generating a three-dimensional layered object (T) through the deposition of a first liquid (9) and of a second liquid (11), wherein the first liquid (9) has a first melting temperature (T1) such that when the first liquid (9) is dispensed onto a modeling platform (2) arranged in a coolable print chamber (6), the first liquid changes state, transitioning from a liquid state to a solid state, and the second liquid (11) has a second melting temperature (T2) such that when the second liquid (11) is dispensed onto the modeling platform (2), the second liquid changes state, transitioning from a liquid state to a solid state, the second melting temperature (T2) being higher than the first melting temperature (T1), a) depositing the first liquid (9) on a support surface (3) of the modeling platform (2), the first liquid (9) solidifying immediately upon contact with the support surface (3) to form a first containment layer (H1), the first containment layer (H1) defining an area greater than the area of ​​the largest cross section of a three-dimensional model defining the three-dimensional layered object (T) to be generated; b) planarizing the face (20) of the first restraining layer (H1) facing away from the support plane (3) to create a first flat face (20) that is coplanar with respect to the plane (X_Y) and ensures a constant thickness (D1) of the first restraining layer (H1); c) depositing the second liquid (11) on the previously formed first stop layer (H1), the second liquid (11) solidifying immediately upon contact with the first stop layer (H1) to form a first structural layer (G2) of the three-dimensional layered object (T), the first structural layer (G2) being deposited in an area having a contour corresponding to the contour of a first cross section of a digital model of the three-dimensional layered object (T); d) depositing the first liquid (9) on the first restraining layer (H1), at least in the area not affected by the first structural layer (G2), the first liquid (9) solidifying immediately upon contact with the first restraining layer (H1) to form a second restraining layer (H2) completely surrounding the first structural layer (G2) in the direction X and the direction Y; e) planarizing the face (19a) of the second control layer (H2) facing away from the support plane (3) and the face (19b) of the first structural layer (G2) facing away from the support plane (3), thus making these faces flush and ensuring a constant thickness of the first structural layer (G2) and of the second control layer (H2); f) repeating steps c), d) and e) for all cross sections n of said three-dimensional model, thus generating an object formed by n superimposed structural layers (G2, G3, ... Gi, ... Gn) and surrounded at the bottom and at the sides along the directions X and Y by n+1 blocking layers (H1, H2, ... Hi, ... Hn+1); g) varying the temperature of the print chamber (6) so that it exceeds the first melting temperature (T1) and the restraining layers (H1, H2, ... Hi, ... Hn+1) spontaneously return to a liquid state, releasing the three-dimensional layered object (T) thus formed; A method comprising:

8. 8. The method of claim 7, wherein following steps b) and e), the support plane (3) is moved a predetermined amount relative to the print chamber (6).

9. 9. A method according to claim 7 or 8, wherein following step c), thermal radiation (13) is directed at the lateral edges of the corresponding structural layers (G2, G3, ... Gi, ... Gn), the lateral edges of the corresponding structural layers (G2, G3, ... Gi, ... Gn) being perpendicular to the plane (X_Y), this thermal radiation (13) resulting in melting of the edges, which then solidify, reducing the graininess of the edges themselves.

10. 9. The method according to claim 7 or 8, wherein a uniform thermal irradiation of the previously deposited structural layers (G2, G3, ... Gi, ... Gn) is applied.

11. 11. The method according to any one of claims 7 to 10, wherein in step d) the second stopping layer (H2) is deposited only in areas not affected by the first structural layer (G2).

12. The second stopping layer (H2) is deposited both on the first structural layer (G2) and on the areas not affected by the first structural layer (G2), followed by step e):

11. The method according to any one of claims 7 to 10, which contributes to expelling the solidified first liquid (9) disposed on the first structural layer (G2).

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